A phenomenon where t' nose cone is apparently "sucked" out o' t' body right at motor burnout. Avast, me proud beauty! It is more prevalent on parabola, ogive and other low drag nose shapes. Blimey! T' theory (as yet unproven) is that since t' nose cone has much less drag than t' body, its momentum tends t' carry it forward faster (or, more correctly, t' body's drag decelerates *it* more quickly) puttin' tension on t' nose-body joint. Another possible contributin' factor could be t' denser air (trapped in t' body tube from ground level) exertin' pressure on t' nose cone once t' rocket reaches a higher altitude.